Lido stETH depeg history and recovery mechanics from Terra to Curve Wars

Lido’s stETH token lost its 1:1 peg with Ethereum in June 2022, dropping to 0.98 ETH as the broader market fractured. This specific event exposed a structural flaw in liquid staking protocols where arbitrage mechanisms could only push prices up, not down. The collapse of TerraUSD (UST) in May 2022 had already demonstrated how algorithmic systems fail under pressure, but stETH revealed a different kind of fragility tied to withdrawal constraints. Investors who held stETH faced immediate losses because they could not redeem their tokens for ETH while the price remained depressed. The situation required complex DeFi interventions to stabilize the market before the ecosystem could recover.

Structural flaws and the death spiral

The Terra ecosystem collapsed after losing $50 billion in market value when UST depegged from the dollar. LUNA, the native token used to absorb volatility, fell by more than 99% within weeks. The system relied on an algorithm that minted or burned LUNA to keep UST at $1, but this mechanism failed during a "death spiral." As UST traded below $1, arbitrage traders stopped buying it because minting LUNA no longer generated profit. This lack of demand caused UST holders to sell, driving the price further down. Anchor Protocol, which promised nearly 20% annual yield, saw billions in withdrawals starting May 7, 2022. Do Kwon’s team withdrew 150 million UST from Curve’s 3pool liquidity pool, accelerating the selling pressure. The interplay between these factors created a feedback loop that no amount of capital injection could stop.

The stETH arbitrage trap

stETH uses a rebase mechanism to distribute staking rewards by increasing the balance of tokens in user wallets daily. Unlike coupon bonds that pay cash interest, this design theoretically keeps stETH pegged 1:1 with ETH because the reward is embedded in the asset count. However, a critical issue emerged during Ethereum’s transition to Proof of Stake. Users could deposit ETH into Lido to receive stETH, but they could not withdraw ETH back out until the Shanghai upgrade. This restriction removed the downward arbitrage path. If stETH traded at 0.99 ETH, traders could not buy the cheap token and redeem it for full-value ETH to capture the difference. The upward arbitrage still worked, pushing prices toward 1.01 ETH, but nothing forced the price back up from below. A large holder sold their entire stETH position on Curve, triggering the initial depeg. Without the ability to redeem, the market lacked the natural correction force needed to restore the peg quickly.

Curve mechanics and final resolution

Curve Finance’s Stableswap mechanism played a decisive role in preventing a total collapse. Unlike standard constant product market makers, Stableswap maintains a 1:1 peg even when liquidity becomes heavily imbalanced. In the ETH-stETH pool, stETH comprised about 68% of the volume, yet the price stayed near 0.98 ETH rather than crashing to 0.80 ETH. This damping effect bought time for Celsius and other distressed lenders to manage their positions without immediate liquidation cascades. The protocol’s amplification factor, set to 50, ensured that price deviations remained manageable despite extreme supply shifts. Once the Shanghai upgrade allowed validators to withdraw staked ETH, the arbitrage loop closed. Traders could finally redeem stETH for ETH, creating upward pressure that erased the remaining discount. Lido’s TVL grew by 15% following the launch of Lido V2, which facilitated easier conversion back to ETH. The market cap of stablecoins has since grown to $261 billion, showing that the sector learned from these failures. Will future liquid staking tokens face similar withdrawal bottlenecks during network upgrades?